Shingle



Aug; 10, 1937.

o. J. KUHN 2,089,489

SHINGLE Filed Aug. 5, 1935 2 Sheets-Sheet l MTNESS fil w TiORHEY Aug. 10, 1937. o. J. KUHN 2,089,489

SHINGLE Filed Aug. 5, 1935 2 Sheets-Sheet 2 Patented Aug. 10, 1937 UNETEE STATES PATENT OFFICE SHINGLE This invention relates to a new and improved asphaltum or equivalent pliable shingle and to the method of laying such shingles so as to form a weather proof roofing or siding construction.

The shingles comprising this invention are laid in successive courses with the contiguous ends of the shingles of each course arranged in overlapping relation in what is known as the Dutch lap method. It is the usual practice in laying shingles by this method to nail the shingles to the roof boards or siding in such a manner that when successive courses are laid, they will cover the heads of the securing nails. Since this nor mally leaves the exposed corner of each shingle without a fastening nail directly connected therewith, I provide each shingle with a holding means preferably formed integral therewith adapted to cooperate with the adjacent shingle of the same course for securing the exposed corner of the shingle in position, thereby permitting the use of relatively large shingles which greatly expedite the task of laying the shingles and effect further economy as a result of a'much higher ratio of exposed area to the over-lap area.

It is an object of this invention to provide a shingle having a unitary locking means in the form of a flap or extension that is folded under the main body portion of the shingle and in service is adapted to be brought under the lower edge of an adjacent shingle in the same course and under the adjacent side edge of a shingle .in the preceding course, thus providing for securing each shingle at three spaced positions along the lower edge thereof so as to prevent the central portion of each shingle from warping upwardly or from being lifted by the wind.

Another object of the invention is to provide a reversible shingle so constructed that either longitudinal side thereof may be positioned to form the base or lower edge of the corresponding course whereby a selected one of at least two distinctive designs of roofing or siding may be 7 formed with the same shingles.

A further object of the invention is 'to provide reversible shingles having gauge means so arranged that in whichever position the shingles are laid, the amount of lap of each shingle upon the adjacent portion of the underlying shingle or shingles may be readily determined thereby.

A still further object of the invention is to provide an interlocking shingle in which the interlocking means are so-constructed as to permit the lower over-lapping edge of the main body portion of the shingle to lie flat upon the under- 55 lying shingle.

Syracuse, N. Y.

1935, Serial No. 34,676

Other objects and advantages relate to the specific form of the shingle and to the method of laying the same, all as will more fully appear in the following description taken in connection with the accompanying drawings in which:

Figure l is a plan view of a shingle embodying the various features of this invention.

Figure 2 is a transverse sectional view on an enlarged scale taken substantially in the plane of the line 22, Figure 1, and illustrating the 10 flaps or extensions of the shingle folded under the main body portion thereof.

Figure 3 shows a portion of a roof or siding covered with one arrangement of theshingles of my invention, portions of the shingles being -15 broken away to show the interlocking features of the invention.

Figure 4 is a view similar to Figure 3, illustrating a second arrangement of my shingles for producing a roofing or siding which is distinctive from the roofing or siding shown when the shingles are laid in the reverse manner as illustrated in Figure 3.

Figure 5 is a plan view of a portion of a sheet of roofing material showing the manner of cutting the shingles therefrom.

Figure 6 is a perspective view illustrating a modified form of shingle as the same is cut from a sheet of asphaltum or other suitable material.

Figure '7 is a perspective View of the left hand portion of the shingle shown in Figure 6 with the interlocking extension or flap folded under the main body portion of the shingle as used in service.

Figure '8 shows a portion of a roof or siding I covered with shingles formed in the manner disclosed in Figures 6 and '1, portions of the shingles being broken away to show the interlocking features of the invention.

Figure 9 is a perspective view showing further details of the interlocking features and the position of the lower edge of the main body portion of the shingle.

The shingle as shown in Figures 1 to 5 inclusive, is made in the form of a trapezoid and comprises a main body portion I having its opposite longitudinal edges 2 and 3 substantially parallel, while its opposite end edges 4 and 5 are disposed at an angle to each other. One of the end edges as 4 is substantially straight and disposed at right angles to the'longitudinal center and, therefore, to the opposite lengthwise edges of the shingle. The other end edge 5 is provided with an intermediate portion 5' disposed diagonally with reference to the longitudinal center and opposite lengthwise edges of the shingle, while the remaining portions of said end as 6 and ii are arranged one at either end of the portion 5 and extend substantially normal to the opposite lengthwise edges of the shingle and, therefore, parallel with the other end a. The vertical portion 6 of the end 5 is positioned outwardly some distance beyond the other vertical portion 6 so that the diagonal portion 5 inclines upwardly and outwardly from portion 5 to portion 6' so that when the shingle is laid with the edge 2 at the lower side, the exposed end of the shingle will extend upwardly and outwardly therefrom as will hereinafter be more apparent.

Theside 2 of the shingle is provided with a relatively long extension or flap i normally projecting from the main body portion and extending inwardly from end portion 5 to substantially the center of edge 2 and is folded inwardly, preferably during the manufacture of the shingle, beneath the adjacent portion of said body I as illustrated in Figure 2 along a line as 8, Figure l, substantially parallel with the edge 2.

When the extension l is folded beneath the body of the shingle, it forms a groove or recess 9 for the reception of the edge 2 adjacent the end 4 of the next adjacent shingle of the same course, and inasmuch as the length of the extension is substantially equal to or slightly less than onehalf the length of edge 2, it will be seen that the degree of side lap between adjacent shingles in the same course may be varied as desired to an appreciable extent, from a relatively short distance to nearly one-half the length of the shingle so as to produce what may be termed a single ply roofing or a double ply roofing.

The flap or extension I is provided at its inner end adjacent the outer edge thereof with a longitudinally projecting interlocking tab Ill which, when the extension is in the folded position, extends inwardly beneath the body I of the shingle toward the end 4 so as to extend beneath an abutting portion of an underlying shingle of the next adjacent lower course as will hereinafter be more apparent.

The edge 3 of the shingle is provided with a flap or extension l arranged in diagonally spaced relation to flap 1 adjacent end i. The flap 1 is preferably of the same length as flap 1 and is adapted to be folded along line 8" to a position beneath the body I of the shingle to form a recess 9. The inner end of flap i, like flap l, is provided with a longitudinally extending locking tab iii also adapted, when the edge 3 of the shingle forms the lower edge of the respective course, to extend beneath the shingle of the next lower course which underlies said shingle.

As illustrated in Figure 5, the shingles may be cut or blanked out of large sheets of material and in order to effect economy, the extensions 7 and i of each shingle are cut from opposite sides respectively of another shingle, thus providing the edges 2 and 3 adjacent the ends l and 5 with corresponding recesses ii and i2 complementary to the extensions i and B respectively. As shown more clearly in Figure 1, each shingle has the diagonal corners adjacent the recesses II and 52 each provided with a pair of notches or indicia arranged in the corresponding longitudinal side and end surface of the shingle. The notches or indicia as I3 and it provided in the longitudinal edges 2 and 3 respectively serve as guides in laying the successive shingles in a predetermined course when forming the single ply covering, both when the shingles are laid with the side 2 forming the lower edge and when laid in the reverse order wit the side 3 forming the lower edge. The notch i3 is spaced from the end 3 a distance to provide ample side lap with the next shingle over the end 4 while the notch M is spaced from the end portion 5' a distance equal to the distance the notch i3 is spaced from the end Q plus the excess length of the side 3 over the side 2. In other words, the relation of the notches i3 and i i to the respective adjacent ends of the shingle is such that when the adjacent ends of two shingles of the same course are arranged in overlapping relation with the notches i3 and M in registration with a corresponding longitudinal edge of the shingles, the shingles will be positioned in substantially longitudinal alignment with each other and thus greatly facilitate the laying of the shingles.

The spacings of the remaining two notches as 55 and i6, provided in the ends, from the adjacent longitudinal edge of the shingle are equal to the amount of head lap of one course upon the next preceding course and are, therefore, equal to each other so that irrespective of which longitudinal edge of the shingle forms the lower edge of the course, one of the notches !5 or i6 is adapted to receive the inner end of a flap 5 or F of the shingle of the next upper course therein, while the other end notch will align with the upper edge of the underlying shingle of the next preceding course.

Before the shingles are applied to a roofing or siding, the flaps or extensions 1 and l are folded as shown in Figure 2 under the main body portion of the shingle so that the folded edges 8 and 8' form substantially a continuation of the longitudinal edges i9 and E9 of the recesses H and i2 respectively. This is preferably done at the factory where the sh ngles are out, so that the shingles are shipped to the roofer in a completely pro-formed condition.

As hereinbefore stated, my novel shingles are adapted to be laid in courses from the bottom or lower edge of the siding or roofing upwardly and those of each course are laid from the left hand toward the right hand side of the siding or roofeach course are laid with the longitudinal edge 2 lowermost and their opposite edges 3 uppermost, thus bringing the end 5 of the shingle in an exposed position at the left hand side and the straight end A in a concealed position at the right hand side in each course.

More specifically, when laying the shingles to form the roofing or siding construction illustrated in Figure 3, the lower left hand shingle is first placed in the operative position with its longitudinal edge 2 in alignment with the lower or bottom edge of the siding or roofing and with the end portion 6 of the end 5 aligned with the corresponding edge of the underlying structure. A nail as a is then driven through the right hand lower corner of the shingle in greater spaced relation to the lower edge of the shingle than the width of the underlying portion of the tab i, after which the opposite or left hand end of the shingle may be secured to the underlying structure by inserting nails or other fastening means of the first shingle, after which the second shingle is moved longitudinally relative to the first shingle either toward the right or toward the left hand side to bring the end portion 6 thereof into registration with the notch [3 of the first shingle and then the second shingle is swung to bring the notch l4 thereof into registration with the upper portion of the end edge 4 of the first shingle. The shingle is then secured into position by driving a nail as a through the lower right hand corner of the second shingle and another nail as b through the upper left hand corner of the second shingle and through the upper right hand end portion of the first shingle, thereby securing both shingles to each other and to the supporting structure.

In like manner, each successive shingle of the lower course is placed in operative position and secured to the underlying structure along the entire length of the siding or roofing.

Before laying the shingles of the next or second course, a short shingle section 29, depending in length upon the amount of side lap of the shingles of the first course, is secured by nails or other fastening means to the supporting structure in overlying relation with the first shingle of the first course in a manner which is well known to those skilled in the art to establish a beginning for the shingles of the second course.

The first left hand shingle of the second course may be then placed in operative position by first inserting the tab l8 beneath the left hand end of the second shingle of the first course and then moving the shingle laterally to bring the inner end 2| of the flap 1 into interlocking engagement with the notch iii of the second shingle of the first course, after which fiap 7 is inserted beneath the lower right hand end of section 20 and the first shingle of the second course is then swung laterally to bring the notches or indicia i l and I5 into registration with the edges of the adjoining shingles as illustrated. The shingle of the second course is then secured in position by first driving a nail a through the lower right hand corner of said shingle and the underlying portion of the second shingle of the first course into the supporting structure and then a nail as b is driven through the upper left hand corner of the first shingle of the second course and the underlying portion of the section 20 into the supporting structure.

It is to be understood that the left hand end of the first shingle and the short shingle section 20 of the second course may be additionally nailed or secured to the underlying structure as desired.

The second shingle of the second course is then placed in position by first bringing the end 2| of the fiap 1 thereof into interlocking engagement with the notch iii of the third shingle of the first course and the fiap I of said second shingle of the second course beneath the lower right hand edge of the first shingle of the second course in the manner hereinbefore described for the first shingle of the second course after which the second shingle of the second course is secured to the adjacent shingles and to the underlying structure by driving a, nail a through the lower right hand corner and another nail or fastening means b through the upper left hand corner of said shingle in the manner hereinbefore described for the first shingle of the second course.

In like manner, succeeding shingles of the second course are laid and secured in proper alignment with each other and-in proper overlapping relation with the shingles of the first course, these operations for the several courses being continued throughout the length of the supporting structure.

It is, of course, understood that when the roofing or siding is completed, any protruding ends of the shingles beyond the ends of the supporting structure will be cut off in alignment with the corresponding edge of said structure.

If, however, it is desired that the vertical shadow line of the shingles extend transversally of the siding or roofing in planes substantially normal to the longitudinal sides thereof, this may be readily accomplished as shown in Figure 4, by using the same shingle comprising the structure shown in Figure 3 but merely reversing the position of the shingles, or in other words, by laying the shingles with the edge 3 thereof lowermost.

In constructing the form of siding or roofing shown in Figure 4, substantially the same mode of procedure in laying the shingles is followed as that described above for the structure shown in Figure 3, that is, a shingle is positioned to the lower left hand corner of the supporting structure with the longitudinal edge 3 of the shingle in alignment with the longitudinal edge of the supporting structure, while the straight end edge 4 of the shingle is aligned with the corresponding vertical edge of the supporting structure. This first shingle of the first course is then secured in position by driving fastening means as nails a and I) through the lower right hand and the upper left hand corner respectively of the shingle in the manner described for the first shingle of the first course in the structure shown in Figure 3.

The second shingle of the first course is then brought into position by inserting the fiap I beneath the lower edge of the first shingle and then the second shingle is moved longitudinally relative to the first shingle to bring the end edge 4 thereof into registration with the notch I 4 provided in the edge 3 of the first shingle after which the second shingle is moved relative to the first shingle to bring the notch l3 thereof into registration with the end portion 6 of the first shingle after which the second shingle is secured to the first shingle and to the underlying structure by inserting fastening means as the nails a and I) through the lower right hand and the upper left hand corners thereof.

The remaining shingles of the first course are then successively laid in the same manner as the second shingle after which the second course is started by securing a shingle section as 20' similar to the shingle section 2B in overlapping relation with the upper edge of the first shingle of the first course.

The first complete shingle of the second course may then be laid by first inserting the tab ill beneath the left hand end 4 of the second shingle of the first course .and moving the first shingle of the second course relative to the shingles of the first course to bring the end as 2! of the flap I into locking engagement with the notch l5 of the second shingle of the first course. The fiap 1' is then inserted beneath the shingle section 20 and moved until the notches l3 and !6 thereof register with the edges of the adjoining shingles as illustrated. The first shingle of the second course is then secured to the adjacent shingles and to the underlying structure by driving nails as a and 12 through the lower right hand and the upper left hand corners thereof.

In like manner, the second shingle and the succeeding shingles of the second course are laid and secured in proper alignment with each other and in proper overlapping relation to the shingles of the first course, these operations for the several courses being continued throughout the length of the structure.

It will now be observed that although I have illustrated but two nails or fastening means for each shingle, the structure as a Whole is securely maintained in position to form a substantial, water-tight covering, due to the fact that each shingle is secured to the underlying structure at least at three spaced places, and in addition to this, the shingles of the second and succeeding courses each have interlocking engagement with two other shingles, one of which is of the next preceding course. Furthermore, this interlocking engagement of each shingle along its lower exposed edge with adjacent shingles is so closely related with the fastening means a and b, that said lower edges of the shingles are securely maintained thereby against warping or being raised by the action of the wind. It will be understood, however, that additional fastening nails or elements may be used if desired, other than that shown for securing the shingles in position. Also, it will be understood that the designs shcwn in Figures 3 and 4 may be combined to produce a third design of covering. That is, alternate courses may be constructed by layin the shingles in the manner taught in Figure 3 with the oblique end 5 of the shingles in the exposed position, while thecourses intermediate said .alternate courses may be formed by laying L the shingles with the square end A in the exposed position as illustrated in Figure 4.

The shingles shown in Figures 6 to 9 inclusive are constructed and applied to a supporting structure in much the same manner as the shin- .40 gle shown in Figures 1 to 5 inclusive, in that each shingle is provided with an under-folded flap or extension as 24 formed integral with one longitudinal edge of the body 25 of the shingle adjacent an end thereof while a complemental 45 recess 25 is formed in the opposite longitudinal edge of the shingle. Furthermore, the flapor extension 24- is provided with a holding tab 21 which extends inwardly longitudinally of the flap adjacent the outer longitudinal edge thereof, and 50 which is adapted to extend beneath an adjacent shingle of the next preceding course to bring the flap Z into interlocking engagement therewith in the same manner in which the tabs l0 and ill engage the adjacent shingles of the struc- 55 ture shown in Figures 3 and 4.

The shingle shown in Figures 6 to 9 inclusive, however, is substantially rectangular in general outline, while one longitudinal edge only is provided with the flap or extension 24. Along 60 the end edge 28 adjacent the recess 26 is provided a notch 2f! adapted, like notches l5 and it, to serve as a guide and also, to cooperate with the shingle interlocking means during the laying of the shingles. An incision 38 may be 65 made extending inwardly from the lower edge 3! parallel with the right hand edge 32 of the shingle, and is spaced from said edge a distance corresponding to the intended longitudinal overlap between adjacent shingles of the same course.

70 A guide line 33 may also be provided along the right hand edge 32 to indicate the amount of head lap between successive courses in the same manner in which notches l3 and M are used in the shingle shown in Figure 1.

75 The shingles constructed in the manner shown in Figure 6 are laid in courses extending longitudinally of the supporting structure with the left hand end of the shingles of each course overlapping the right hand end of an adjacent shinle of the same course, while the shingles of succeeding courses have the lower edges thereof arranged in overlapping relation with the upper edge of the shingles of the next preceding course as clearly illustrated in Figure 8.

In other words, when laying the shingles shown in Figure 6, the flap 24 is inserted beneath the lower edge of the right hand end portion of the shingle of the course being laid as illustrated at X, and then the shingle is moved longitudinally of the course to bring the tab 2? beneath the left hand end of an adjacent shingle of the next preceding course with the inner edge 2 of the flap in registration with the notch 29 of said shingle of the preceding course.

Proper alignment of the shingles is maintained in each course by pivoting the shingle being laid about the notch 29 with which the flap 24 is in engagement until guide line 33 coincides with the upper edge of the shingle of the preceding course with which the shoulder 26 engages. After the shingle is thus positioned, it is secured to the adjacent shingles and to the underlying structure by driving a nail as a into the lower right hand corner of the shingle and a second nail as b into the upper left hand corner of the shingle between the notch 29 and the recess 26 as clearly illustrated in Figure 8.

It will thus be seen that flap 24, in this instance, as in the case of the shingle shown in Figure 1, functions to secure the lower left hand exposed corner of each shingle to the lower portion of a shingle of the same course, while the tab 21 and shoulder 24' have interlocking engagement with the left hand upper corner of an adjacent shingle of the next preceding course for further securing the exposed corner of the shingle in position, and at the same time the engagement of the shoulder 2 of a shingle of one course with the notch 29 of an adjacent shingle of the next lower course will prevent relative displacement transversally of the shingles of adjacent courses. The relation of the incision 3?! to the length of the flap 24 and notch 29 is such that when the flap of the shingle of one cour e is in cooperative relation with the underlying shingle of the same course and an adjacent shingle of the next preceding course, said incision will coincide with the end 28 of the overlying shingle so as to permit the lower edge portion of the body of the shingle to lie fiat upon the underlying shingle of the next lower course as clearly illustrated in Figure 9.

Although I have shown and particularly described a preferred form of shingle and one modification thereof which embodies certain novel interlocking features and guides to assist in the laying of the shingles, it is to be understood that these were for illustrative purposes only and that I do not wish to be limited to the exact construction shown as certain changes and modifications may be made by those skilled in the art without departing from the spirit of the invention as set forth in the appended claims.

I claim:

1. A flat shingle of substantially trapezoidal form adapted to be laid with either parallel side forming the lower edge of the shingle and having one end inclined at an obtuse angle to the parallel sides, each of said parallel sides of the shingle having an integral retrovertible flap adapted, when the respective side forms the lower edge of the shingle, to have interlocking engagement with the under side of the adjacent portion of another shingle of the same course.

2. A shingle as in claim 1 wherein the retrovertible flaps are of substantially the same length so as to provide for equal overlapping or" the shingles of the same course, irrespective of which of the two parallel sides of the shingle forms the lower edge thereof.

3. A fiat shingle of substantially trapezoidal form adapted to be laid with either parallel side forming the lower edge of the shingle and hav- 5 ing one end inclined at an obtuse angle to the parallel sides, each of said parallel sides of the shingle having an integral retrovertible flap adapted, when the respective side forms the lower edge of the shingle, to have interlocking 20 engagement with the under side of the adjacent portion of another shingle of the same course, each end of said shingle being provided with a notch adapted to respectively receive the inner end or" the flap of an adjacent shingle therein of 25 the next succeeding course to form a lock and to coincide with an edge of an adjacent shingle of the next preceding course to form a guide whichever of the two parallel sides of the shingle forms the lower edge thereof.

30 4. A fiat shingle of substantially trapezoidal form adapted to be laid with either parallel side forming the lower edge of the shingle and having one end inclined at an obtuse angle to the parallel sides, each of said parallel sides of the shingle having an integral retrovertible flap adapted, when the respective side forms the lower edge of theshingle, to have interlocking engagement with the under side of the adjacent portion of another shingle of the same course,

40 each end and side of said shingle being provided with an interlocking and guide notch respectively, arranged in predetermined relation with each other and said ends and sides so as to cooperate with the flap and edge of adjacent shingles of 45 the same course and of a next preceding course, irrespective of which of the two parallel sides of the shingle forms the lower edge thereof.

5. A roof construction comprising a plurality of flexible shingles laid in courses, the adjacent 50 ends of the shingles of each course being arranged in lapping relation and the adjacent lengthwise edges of the shingles of the several courses being also arranged in lapping relation, each of said shingles having a retrovertible flap 55 extending from its lower edge adjacent an end edge thereof, the lower edge of each of said shingles having an incision normal thereto of greater length than the width of the flap and spaced from the edge opposite the end carry- 60 ing said flap a distance substantially corresponding to the side lap of adjacent shingles in the same course, said shingles being laid so that each shingle has that portion thereof between the incision and adjacent end of the shingle 65 lying in the pocket formed between the main body and the flap of the adjacent shingle in the same course, and the portion of the main body of each shingle adjacent the incision lying fiat upon the underlying shingle of the preceding 70 course.

6. A roof construction comprising a plurality of flexible shingles laid in courses, the adjacent ends of the shingles of each course being arranged in lapping relation and the adjacent lengthwise edges of the shingles of the several courses being also arranged in lapping relation, each of said shingles having a retrovertible flap extending from its lower edge adjacent an end edge thereof, the lower edge of each of said shingles having an incision normal thereto of greater length than the width of the flap and spaced from the edge opposite the end carrying said flap a distance substantially corresponding to the side lap of adjacent shingles in the same course, said shingles being laid so that each shingle has that portion thereof between the incision and adjacent end of the shingle lying in the pocket formed between the main body and the flap of the'adjacent shingle in the same course and the portion of the main body of each shingle adjacent the incision lying fiat upon the underlying shingle of the preceding course, said flap having a portion extending beyond the adjacent end of the corresponding shingle in underlying relation with said abutting end portion of the adjacent shingle in the preceding course.

7. A roof construction as in claim 6 wherein each shingle has the end thereof adjacent the flap provided with an inwardly extending guide notch spaced from the upper edge of the shingle a distance substantially corresponding to the head lap between courses of shingles and adapted to receive an edge portion of the flap of a shingle of the succeeding course therein to form a lock therebetween.

8. A roof construction comprising a plurality of flexible shingles laid in courses, the adjacent ends of the shingles of each course being arranged in lapping relation and the adjacent lengthwise edges of the shingles of the several courses being also arranged in lapping relation, each of said shingles having a retrovertible flap extending from its lower edge adjacent an end edge thereof, said flap having an extension at its inner end for extending beneath the abutting end of the shingle of the preceding course, the lower edge of each of said shingles having an incision normal thereto of greater length than the width of the flap and spaced from the edge opposite the end carrying said flap a distance substantially corresponding to the side lap of adjacent shingles in the same course, said shingles being laid so that each shingle has that portion thereof positioned between the incision and the adjacent end of the shingle lying in the pocket formed between the main body and the flap of the adjacent shingle in the same course and the portion of the main body of each shingle adjacent the incision lying flat upon the underlying shingle of the preceding course, each of said shingles also having the end thereof adjacent the flap provided with an inwardly extending guide notch spaced from the upper edge of the shingle a distance substantially corresponding to the head lap between courses of shingles and adapted to receive an edge portion of said flap extension of a shingle of the succeeding course therein to form a lock therebetween.

9. A roof construction comprising a plurality of flexible shingles laid in courses, the adjacent ends of the shingles of each course being arranged in lapping relation and the adjacent lengthwise edges of the shingles of the several courses being also arranged in lapping relation, each of said shingles having a retrovertible flap connected with its lower longitudinal edge adjacent an end edge thereof and normally spaced from the adjacent portion of the main body of the shingle to form a pocket therebetween, said shingles being laid so that each shingle has at least a portion of the lower edge adjacent the end opposite the flap thereof lying in the pocket formed between the main body portion and the flap of an adjacent shingle of the same course, and means including a roofing nail driven through each shingle at the corner adjacent the portion thereof lying in said pocket for securing the shingles to a supporting structure, said flaps of the shingles of each course being located in a plane wholly below said roofing nails for the corresponding course whereby each shingle and the flap connected therewith may be moved longitudinally of the adjacent shingle of the same course engaged in the pocket formed thereby to vary the degree of side lap of said adjacent shingle from a relatively short portion of its length to substantially one-half the length thereof to provide either a single-ply roofing or a double-ply roofing.

10. A roof structure as in claim 9 wherein the length of each retrovertible flap is equal to substantially one-half the length of the lower side of the shingle whereby said flap will have engagement with the lower side portion of the adjacent shingle in the same course engaged in the pocket formed thereby the full length of the side lap of said latter shingle whether a singleply roofing or a double-ply roofing is formed.

11. A roof structure as in claim 9 wherein each shingle has the lower edge thereof opposite the flap provided with a guide mark spaced from the adjacent end edge thereof a distance substantially corresponding to the smallest degree of side lap of said shingle with the adjacent shingle of the same course.

12. A roof structure as in claim 9 wherein each shingle is provided with an incision of greater length than the width of the flap extending inwardly from the lower edge thereof opposite the flap substantially normal thereto and spaced from the adjacent end of the shingle a distance substantially corresponding to the side lap thereof with the adjacent shingle of the same course so that the portion of said shingle between the incision and adjacent end thereof will lie in the pocket formed between the main body and the flap of said adjacent shingle of the same course and the portion of the main body of said shingle adjacent the inner side of the incision will lie flat on the underlying shingle of the preceding course.

13. A flat shingle having at least two parallel sides adapted to be laid with either parallel side forming the lower edge of the shingle, each of said parallel sides of the shingle having an integral retrovertible flap folded beneath the under side of the shingle and adapted when the respective side forms the lower edge of the shingle to have interlocking engagement with the underside of the adjacent portion of another shingle of the same course, said flaps being arranged at opposite ends of the shingle to extend inwardly therefrom a distance not to exceed one-half the length of the respective side.

14. A shingle as in claim 13 wherein the retrovertible flaps are of substantially the same length so as to provide for equal side lapping of the shingles of the same course irrespective of which of the two parallel sides of the shingle forms the lower edge thereof.

OTTO J. KUHN. 

